Farmed land, by its nature, undergoes cyclic periods of sowing, growth, and harvest. Sowing, growing, and harvesting of crops require certain conditioning of the soil if successful returns are going to be obtained from the worked area. Conditions left over a farmed area, particularly after harvest, do not normally provide the ideal conditions in which further crops can be sowed. When the main crop is harvested, the soil often includes weeds that need to be destroyed as well as stubble and the like from previous crops requiring uprooting and cutting before any seed can be sowed. Not only does stubble require uprooting or cutting and weeds still need to be killed off, but there is also the further requirement of having the soil leveled such that sowing implements responsible for reintroducing a new crop into the field can do so efficiently and expeditiously. Thus, it may be important to cultivate the surface of the soil. An agricultural implement including a harrowing chain may be used for this purpose. This operation may be distinct in its effect from a ploughing operation, which is typically used for deeper cultivation. Harrowing is often carried out on fields to follow the rough finish left by ploughing operations. The purpose of harrowing is to generally break up clods and lumps of soil and to provide a finer finish, a good tilth, or soil structure that is suitable for seeding and planting operations. Such coarser harrowing may also be used to remove weeds and to cover seed after sowing. Often a harrowing implement is pulled over the land by a tractor. The harrowing implement may be a useful tool for farming rice, corn, wheat, beans, milo, and sunflowers.
Harrowing agricultural implements are common in the art. Examples of harrowing agricultural implements include U.S. Pat. No. 5,881,820 (“Baker”) and U.S. patent application Ser. No. 11/765,182 (Pub. No. U.S. 2008-0314606 A1) (“Kelly”).
During normal operation, slack may increase in the harrowing chain to the point that it no longer rotates but rather bounces along the ground. Also, harrow disks in the harrowing chain may become dull or broken causing less effective cultivation.